Locking tabs for cardboard containers



May 25, 1965 F E. FOBIANO ETAL 3,185,381

LOCKING TABS FOR CARDBOARD CONTAINERS Filed June 13, 1963 2 Sheets-Sheet 1 riana/71:

2 Sheets-Sheet 2 F. E. FOBIANO ETAL LOCKING TABS FOR CARDBOARD CONTAINERS INVENTOR-i United States Patent Office Patented May 25, 1965 3,185,381 LOCKING TABS FOR CARDBOARD CONTAINERS Frank E. Fobiano and Joseph S. Haven, Cincinnati, Ohio, assignors to Premier Carton Company, Cincinnati, Ohio, acorporation of Ohio Filed June 13, 1963, Ser. No. 287,658 2 Claims. (Cl. 229-35) This invention relates to cardboard containers and more a particularly the invention is directed to locking tabs which cooperate to hold the containers in an erect condition ready to receive the goods to be packaged in the container.

An objective of the invention has been to provide lockiug tabs which can be easily interengaged to locked condition by automatic machinery, the construction :of the locking tabs being such as to eliminate insofar as possible the damage to cartons occasioned by improper locking.

The invention will be described in connection with a boat container, that is a container having a bottom wall, side and end walls which is used largely in the packaging of comestibles such as cookies. It should be understood that the locking tab configuration is not necessarily restricted to that type of container. The boat container is for-med from a one-piece blank having bot-tom, side and end panels, the side panels having lock tabs extending from their ends and locking together across the end panels by means of interengaging slits in the tabs to maintain the carton in an erect condition. The one-piece blank is converted to a boat by the means of forming dies. One stroke with respect to the forming dies folds the side and end panels upwardly, bends the lock tabs toward each other and in proper sequence brings the slits of the tabs into interengagement. The last part of the operation, that is the interengagement of the slits, is the most critical to the formation of the boats. It is of utmost importance to provide a cooperating pair of locking tabs which can be moved easily together and which, when interengaged, will hold the boat in a neat erect condition with the side panels being held firmly against the end panels. If the tab configuration results in a sloppy lock, the package is not only unsightly but the possibility of wicking (capillary flow of grease through the cellulosic material which forms the cardboard) through the side and end panel joints is increased.

If the interengaging slits are designed to provide a secure lock, it is likely that the process of interengaging the slits is difficult with the consequence that there will be a high number of rejects out of the automatic folding machine. On the other hand, if the lock tab slits are designed for easy interengagement, there is a likelihood that the resultant container will have a sloppy lock and the side and end panels will not maintain the desired perpendicular relationship with the bottom panel.

We have found that by providing the lock tabs with cooperating V notches, the Vs tapering int-o crescent shaped slits, the two desired characteristics are attained more satisfactorily than has heretofore been possible with any known lock tab design. The lock tabs move into interengagement easily and when interengaged form a neat, secure lock.

The objectives of the invention will become more readily apparent from the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a perspective view of the container employing the invention,

FIGS. 2, 3 and 4 are end elevational views illustrating the steps for eliecting the interengagement of the lock tab, FIG. 5 is a cross sectional view taken along line 55 of FIG. 1, and a FIG. 6 is a plan view of a one-piece blank from which the boat container is formed.

Referring to the drawings, particularly FIG. 6, the boat container is formed from a one-piece blank 10 having a bottom panel 11, end panels 12 and side panels 13. The end and side panels are hinged to the bottom panel along creases 15 and 16 respectively which form the fold line about which the panels swing when the container is erected.

Hinged to the end of the side panels are locking tabs 17 and 18. The locking tabs 17 have, on what will b their lower edges when the container is formed, a V notch 20 having an apex 21. Extending from the apex 21 to gird the free end 22 of each tab is a crescent shaped slit Similarly locking tabs 18 have, on what will be the upper edge of the tab when the container is erected, a V notch 25 having an apex 26. -A crescent shaped slit 27 extends from the apex 26 toward the free end 28 of each tab. The crescent 27 is slightly longer than the crescent 23 for reasons which will be set forth below.

In the t'or-mation or erection of the container, the end panels 12 are folded to a position perpendicular to the bottom panel 11 and the side panels 13 are similarly folded into position. The side panel containing locking tabs 18 is folded into final position slightly ahead of the other side panel. As the tabs 17 and 18 approach each other, their end portions 30 and 31 move into the V notches 20 and 25 into an underlying relationship with respect to the adjacent lock tab. As the tabs move together, the slits interengage. The slit 27 is made slightly longer than the slit 23 to permit the underlying portion 31 to bend in toward the end panel 12 to facilitate the introduction of the lock tab 17. The crescent slit 23 on the other hand is made short so that when the complete engagement of the slits is effected as illustrated in FIGS. 4 and 5, a tight fit between the lock tabs, with the end panels in perfectly erect condition is effected.

As best illustrated in FIG. 5, when there is a final interengagement of the crescent slits, the cardboard halfrnoons which they define, indicated at 32 and 33, provide books or projections which securely retain the tabs in locking engagement.

We claim:

1. A cardboard boat container comprising,

a rectangular bottom panel,

end panels hinged to the end edges of said bottom panel,

side panels hinged to the side edges of said bottom panel, a

a lock tab hinged :at each end of each side panel to provide a pair of cooperating lock tabs at each end of said boat,

a first of said tabs at each end of said heat having in its upper edge a V notch and a crescent slit extending from the apex of the V toward the lower edge and the free end of said tab,

a second of said tabs at each end of said boat having in its lower edge a V notch and a crescent slit extending fir-om the apex of the V toward the upper edge and the 'free end of said tab, and

said first and second tabs overlying said end panel and having their slits interengaged with the end portion of each t-ab lying between said end panel and the adj acent tab to lock the tabs together.

2. A cardboard boat container comprising,

a rectangular bottom panel,

end panels hinged to the end edges of said bottom panel,

side panels hinged to the side edges of said bottom panel,

a lock tab hinged at each end of each side panel to provide a pair of cooperating lock tabs at each end of said boat,

a first of said tabs at each end of said boat having in its upper edge a V notch and a crescent slit extending from the apex of the V toward the free end of said tab,

a second of said tabs at each end of said boat having in its lower edge a V notch and a crescent slit extending from the apex of the V toward the free end of said tab,

the crescent slit of said first tab being longer than the crescent slit of said second tab, and

said first and second tabs overlying said end panel and having their slits interengaged with the end portion of each tab lying between said end panel and the adjacent tab to lock the tabs together.

References Cited by the Examiner UNITED STATES PATENTS FRANKLIN T. GARRETT, Primary Examiner. 

1. A CARDBOARD BOAT CONTAINER COMPRISING, A RECTANGULAR BOTTOM PANEL, END PANELS HINGED TO THE END EDGES OF SAID BOTTOM PANEL, SIDE PANELS HINGED TO THE SIDE EDGES OF SAID BOTTOM PANEL, A LOCK TAB HINGED AT EACH END OF EACH SIDE PANEL TO PROVIDE A PAIR OF COOPERATING LOCK TABS AT EACH END OF SAID BOAT, A FIRST OF SAID TABS AT EACH END OF SAID BOAT HAVING IN ITS UPPER EDGE A V NOTCH AND A CRESCENT SLIT EXTENDING FROM THE APEX OF THE V TOWARD THE LOWER EDGE AND THE FREE END OF SAID TAB, A SECOND OF SAID TABS AT EACH END OF SAID BOAT HAVING IN ITS LOWER EDGE A V NOTCH AND A CRESCENT SLIT EXTENDING FROM THE APEX OF THE V TOWARD THE UPPER EDGE AND THE FREE END OF SAID TAB, AND SAID FIRST AND SECOND TABS OVERLYING SAID END PANEL AND HAVING THEIR SLITS INTERENGAGED WITH THE END PORTION OF EACH TAB LYING BETWEEN SAID END PANEL AND THE ADJACENT TAB TO LOCK THE TABS TOGETHER. 